public class Test {
    public static void main(String[] args) {
        String str="liang ";
        String str2="zai";
        int a=10;
        int b=20;
        System.out.println(str+(a+b));
    }
    public static void main2(String[] args) {
        System.out.println("hello world!");
    }

    public static void main1(String[] args) {
        int a = 0;
        System.out.println(a);
    }
}
